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Isoquinolinone is an important heterocyclic framework in natural products and biologically active molecules, and the efficient synthesis of this structural motif has received much attention in recent years. Herein, we report a (phenyliodonio)sulfamate (PISA)-mediated, solvent-dependent synthesis of different isoquinolinone derivatives. The method provides highly chemoselective access to 3- or 4-substituted isoquinolinone derivatives by reacting o-alkenylbenzamide derivatives with PISA in either acetonitrile or wet hexafluoro-2-isopropanol.
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Chiral molecular assemblies have attracted considerable attention because of their interesting physical properties, such as spin-selective electron transport. Cation-anion salts of three azolium cations, imidazolium (HIm+), triazolium (HTrz+), and thiazolium (HThz+), in combination with a chiral camphorsulfonate (1S-CS-) and their racemic compounds (rac-CS-) were prepared and compared in terms of phase transitions, crystal structures, dynamics of constituent molecules, dielectric responses, and proton conductivities. The cation-anion crystals containing HIm+ showed no significant difference in proton conductivity between the homochiral and racemic crystals, whereas the HTrz+-containing crystals showed higher proton conductivity and lower activation energy in the homochiral form than in the racemic form. A two-dimensional hydrogen-bonding network consisting of HTrz+ and -SO3- groups and similar in-plane rotational motion was observed in both crystals; however, the HTrz+ cation in the homochiral crystal exhibited the rotational motion modulated with translational motion, whereas the HTrz+ cation in the racemic crystal exhibited almost steady in-plane rotational motion. The different motional degrees of freedom were confirmed by crystal structure analyses and temperature- and frequency-dependent dielectric constants. In contrast, steady in-plane rotational motion with the thermally activated fluctuating motion of CS- was observed both in homochiral and racemic crystals containing HIm+, which averaged the motional space of protons resulting in similar dielectric responses and proton conductivities. The control of motional degrees of freedom in homochiral crystals affects the proton conductivity and is useful for the design of molecular proton conductors.
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What is known about this topic?: H10 avian influenza viruses circulate in wild birds and can reassort with other subtypes. H10N8 and H10N3 have previously caused sporadic human infections in China. What is added by this report?: This report documents the first human case of co-infection with avian-origin H10N5 and seasonal H3N2 influenza viruses. Epidemiological investigations identified H10N5 in environmental samples linked to the patient, but no transmission to close contacts occurred. What are the implications for public health practice?: Enhanced surveillance of avian influenza in live poultry markets and poultry populations is crucial for thoroughly characterizing the epidemiology, transmission, and pathogenesis of H10N5 viruses. Strengthening assessments of outbreak control measures is essential to guide effective management.
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Histone chaperones and histone variants play crucial roles in DNA replication, gene transcription, and DNA repair in eukaryotes. Histone chaperones reversibly promote nucleosome assembly and disassembly by incorporating or evicting histones and histone variants to modulate chromatin accessibility, thereby altering the chromatin states and modulating DNA-related biological processes. Cofactors assist histone chaperones to target specific chromatin regions to regulate the exchange of histones and histone variants. In this review, we summarize recent progress in the interplay between histone variants and chaperones in plants. We discuss the structural basis of chaperone-histone complexes and the mechanisms of their cooperation in regulating gene transcription and plant development.
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Chaperonas de Histonas , Histonas , Histonas/metabolismo , Histonas/genética , Chaperonas de Histonas/metabolismo , Chaperonas de Histonas/genética , Plantas/metabolismo , Plantas/genética , Cromatina/metabolismo , Cromatina/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Regulación de la Expresión Génica de las Plantas , Nucleosomas/metabolismoRESUMEN
In [Mn(5-MeOsalen)(Cl)]2(dibenzo[24]crown-8), dibenzo[24]crown-8 formed a supramolecule via multi-point interactions with the [Mn(5-MeOsalen)(Cl)] dimer. The dimer was magnetically isolated with ST = 4 and weak interdimer magnetic interactions. The crystal exhibited single-molecule magnet behaviour with an anisotropic barrier of 26(1) K, which is the highest among the Mn-salen series reported to date.
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Objectives: Coronavirus disease-19 (COVID-19)/influenza poses unprecedented challenges to the global economy and healthcare services. Numerous studies have described alterations in the microbiome of COVID-19/influenza patients, but further investigation is needed to understand the relationship between the microbiome and these diseases. Herein, through systematic comparison between COVID-19 patients, long COVID-19 patients, influenza patients, no COVID-19/influenza controls and no COVID-19/influenza patients, we conducted a comprehensive review to describe the microbial change of respiratory tract/digestive tract in COVID-19/influenza patients. Methods: We systematically reviewed relevant literature by searching the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2023. We conducted a comprehensive review to explore microbial alterations in patients with COVID-19/influenza. In addition, the data on α-diversity were summarized and analyzed by meta-analysis. Results: A total of 134 studies comparing COVID-19 patients with controls and 18 studies comparing influenza patients with controls were included. The Shannon indices of the gut and respiratory tract microbiome were slightly decreased in COVID-19/influenza patients compared to no COVID-19/influenza controls. Meanwhile, COVID-19 patients with more severe symptoms also exhibited a lower Shannon index versus COVID-19 patients with milder symptoms. The intestinal microbiome of COVID-19 patients was characterized by elevated opportunistic pathogens along with reduced short-chain fatty acid (SCFAs)-producing microbiota. Moreover, Enterobacteriaceae (including Escherichia and Enterococcus) and Lactococcus, were enriched in the gut and respiratory tract of COVID-19 patients. Conversely, Haemophilus and Neisseria showed reduced abundance in the respiratory tract of both COVID-19 and influenza patients. Conclusion: In this systematic review, we identified the microbiome in COVID-19/influenza patients in comparison with controls. The microbial changes in influenza and COVID-19 are partly similar.
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Warm ambient conditions induce thermomorphogenesis and affect plant growth and development. However, the chromatin regulatory mechanisms involved in thermomorphogenesis remain largely obscure. In this study, we show that the histone methylation readers MORF-related gene 1 and 2 (MRG1/2) are required to promote hypocotyl elongation in response to warm ambient conditions. A transcriptome sequencing analysis indicates that MRG1/2 and phytochrome interacting factor 4 (PIF4) coactivate a number of thermoresponsive genes, including YUCCA8, which encodes a rate-limiting enzyme in the auxin biosynthesis pathway. Additionally, MRG2 physically interacts with PIF4 to bind to thermoresponsive genes and enhances the H4K5 acetylation of the chromatin of target genes in a PIF4-dependent manner. Furthermore, MRG2 competes with phyB for binding to PIF4 and stabilizes PIF4 in planta. Our study indicates that MRG1/2 activate thermoresponsive genes by inducing histone acetylation and stabilizing PIF4 in Arabidopsis.
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Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Histonas , Vernalización , Arabidopsis/genética , Cromatina , Metilación , Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas Cromosómicas no HistonaRESUMEN
Schizophrenia (SCZ) is a prevalent, severe, and persistent mental disorder with an unknown etiology. Growing evidence indicates that immunological dysfunction is vital in the development of SCZ. Our study aims to uncover potential immune-linked hub genes and immune infiltration characteristics of SCZ, as well as to develop a diagnostic model based on immune-linked central genes. GSE38484 and GSE54913 chip expression data for patients with SCZ and healthy controls were retrieved. Weighted gene co-expression network analysis (WGCNA) was performed to identify major module genes and critical immune-linked genes. Functional enrichment analysis was conducted to elucidate the involvement of key genes in the immunological response to SCZ, along with the examination of their protein interactions. Moreover, 202 peripheral blood samples were examined using the single-sample gene set enrichment analysis (ssGSEA) method to detect distinct immune cell types. Hub immune-linked genes in SCZ were identified using the minimal absolute contraction and selection operator analysis. Receptor profiles of central immune-linked genes were analyzed to distinguish the two groups. Finally, the association between immune-linked hub genes and various types of immune cells was assessed. Our findings revealed ten immune cell types and nine key genes involved in SCZ, including effector memory CD4+ T cells, activated CD8+ T cells, mast cells, naive CD8+ T cells, PBMC, type 17 helper cells (Th17), central memory CD8+ T cells, CD56 bright NK cells, memory B cells, and regulatory T cells. Diagnostic models constructed using LASSO regression exhibited an average area under the curve (AUC) of 0.866. Our results indicate immunological dysfunction as a factor in the development of SCZ. ASGR2, ADRM1, AHANK, S100A8, FUCA1, AKNA, GATA3, AHCYL2, and PTRH2 are the key regulatory genes of immune cells, highlighting their potential as novel therapeutic targets for SCZ.
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Esquizofrenia , Humanos , Esquizofrenia/diagnóstico , Esquizofrenia/genética , Leucocitos Mononucleares , Área Bajo la Curva , Perfilación de la Expresión Génica , Proteínas de Unión al ADN , Proteínas Nucleares , Factores de Transcripción , Péptidos y Proteínas de Señalización IntracelularRESUMEN
Monitoring variations in the virus genome to understand the SARS-CoV-2 evolution and spread of the virus is extremely important. Seven early SARS-CoV-2 isolates in China were cultured in vitro and were analyzed for their viral infectivity through viral growth assay, tissue culture infectious dose (TCID50 ) assay, spike protein quantification, and next generation sequencing analysis, and the resultant mutations in spike protein were used to generate the corresponding pseudoviruses for analysis of immune escape from vaccination and postinfection immunity. The results revealed that in vitro cultured SARS-CoV-2 virus had much higher mutation frequency (up to ~20 times) than that in infected patients, suggesting that SARS-CoV-2 diversify under favorable conditions. Monitoring viral mutations is not only helpful for better understanding of virus evolution and virulence change, but also the key to prevent virus transmission and disease progression. Compared with the D614G reference strain, a pseudovirus strain of SARS-CoV-2 was constructed with a high mutation rate site on the spike protein. We found some novel spike mutations during in vitro culture, such as E868Q, conferred further immune escape ability.
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COVID-19 , Humanos , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Bioensayo , Mutación , InmunidadRESUMEN
Changbai Mountain Nature Reserve (CNR) is a typical temperate forest ecosystem, and gross primary production (GPP) of which is closely related to topography and climate change. Research on the spatio-temporal variations and influencing factors of GPP in the CNR is of great significance for assessing growth status of vegetation and the quality of ecological environment. We calculated GPP in CNR using the vegetation photosynthesis model (VPM), and analyzed the influences of slope, altitude, temperature, precipitation, and total radiation. The results showed that the range of annual average GPP in CNR was 63-1706 g C·m-2·a-1 from 2000 to 2020 and that GPP decreased with the increases of altitude. Temperature played the most important role in driving the spatial varia-tion of GPP, with a significant positive correlation with GPP. During the study period, the overall annual GPP showed a significant increase trend in CNR, with an average annual increase of 13 g C·m-2·a-1. The areas with increase of annual GPP accounted for 79.9% of the total area, and the area proportion of annual GPP increase differed in each plant functional type. Annual precipitation was significantly negatively correlated with GPP in 43.2% of CNR, while annual mean temperature and annual total radiation were significantly positively correlated with GPP in 47.2% and 82.4% of CNR. GPP would increase continuously in CNR under the scenario of future global warming.
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Ecosistema , Bosques , China , Cambio Climático , Calentamiento GlobalRESUMEN
The histone variant H2A.Z plays key functions in transcription and genome stability in all eukaryotes ranging from yeast to human, but the molecular mechanisms by which H2A.Z is incorporated into chromatin remain largely obscure. Here, we characterized the two homologs of yeast Chaperone for H2A.Z-H2B (Chz1) in Arabidopsis thaliana, AtChz1A and AtChz1B. AtChz1A/AtChz1B were verified to bind to H2A.Z-H2B and facilitate nucleosome assembly in vitro. Simultaneous knockdown of AtChz1A and AtChz1B, which exhibit redundant functions, led to a genome-wide reduction in H2A.Z and phenotypes similar to those of the H2A.Z-deficient mutant hta9-1hta11-2, including early flowering and abnormal flower morphologies. Interestingly, AtChz1A was found to physically interact with ACTIN-RELATED PROTEIN 6 (ARP6), an evolutionarily conserved subunit of the SWR1 chromatin-remodeling complex. Genetic interaction analyses showed that atchz1a-1atchz1b-1 was hypostatic to arp6-1. Consistently, genome-wide profiling analyses revealed partially overlapping genes and fewer misregulated genes and H2A.Z-reduced chromatin regions in atchz1a-1atchz1b-1 compared with arp6-1. Together, our results demonstrate that AtChz1A and AtChz1B act as histone chaperones to assist the deposition of H2A.Z into chromatin via interacting with SWR1, thereby playing critical roles in the transcription of genes involved in flowering and many other processes.
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Proteínas de Arabidopsis , Arabidopsis , Ensamble y Desensamble de Cromatina , Chaperonas de Histonas , Adenosina Trifosfatasas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cromatina/metabolismo , Chaperonas de Histonas/genética , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Annual gross primary productivity (AGPP) is the basis for grain production and terrestrial carbon sequestration. Mapping regional AGPP from site measurements provides methodological support for analysing AGPP spatiotemporal variations thereby ensures regional food security and mitigates climate change. Based on 641 site-year eddy covariance measuring AGPP from China, we built an AGPP mapping scheme based on its formation and selected the optimal mapping way, which was conducted through analysing the predicting performances of divergent mapping tools, variable combinations, and mapping approaches in predicting observed AGPP variations. The reasonability of the selected optimal scheme was confirmed by assessing the consistency between its generating AGPP and previous products in spatiotemporal variations and total amount. Random forest regression tree explained 85 % of observed AGPP variations, outperforming other machine learning algorithms and classical statistical methods. Variable combinations containing climate, soil, and biological factors showed superior performance to other variable combinations. Mapping AGPP through predicting AGPP per leaf area (PAGPP) explained 86 % of AGPP variations, which was superior to other approaches. The optimal scheme was thus using a random forest regression tree, combining climate, soil, and biological variables, and predicting PAGPP. The optimal scheme generating AGPP of Chinese terrestrial ecosystems decreased from southeast to northwest, which was highly consistent with previous products. The interannual trend and interannual variation of our generating AGPP showed a decreasing trend from east to west and from southeast to northwest, respectively, which was consistent with data-oriented products. The mean total amount of generated AGPP was 7.03 ± 0.45 PgC yr-1 falling into the range of previous works. Considering the consistency between the generated AGPP and previous products, our optimal mapping way was suitable for mapping AGPP from site measurements. Our results provided a methodological support for mapping regional AGPP and other fluxes.
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Cambio Climático , Ecosistema , Secuestro de Carbono , Suelo , Aprendizaje Automático , Carbono , Dióxido de Carbono/análisisRESUMEN
Reassortment can introduce one or more gene segments of influenza A viruses (IAVs) into another, resulting in novel subtypes. Since 2013, a new outbreak of human highly pathogenic avian influenza has emerged in the Yangtze River Delta (YRD) and South-Central regions of China. In this study, using Anhui province as an example, we discuss the possible impact of H7N9 IAVs on future influenza epidemics through a series of gene reassortment events. Sixty-one human H7N9 isolates were obtained from five outbreaks in Anhui province from 2013 to 2019. Bioinformatics analyses revealed that all of them were characterized by low pathogenicity and high human or mammalian tropism and had introduced novel avian influenza A virus (AIV) subtypes such as H7N2, H7N6, H9N9, H5N6, H6N6, and H10N6 through gene reassortment. In reassortment events, Anhui isolates may donate one or more segments of HA, NA, and the six internal protein-coding genes for the novel subtype AIVs. Our study revealed that H7N9, H9N2, and H5N1 can serve as stable and persistent gene pools for AIVs in the YRD and South-Central regions of China. Novel AIV subtypes might be generated continuously by reassortment. These AIVs may have obtained human-type receptor-binding abilities from their donors and prefer binding to them, which can cause human epidemics through accidental spillover infections. Facing the continual threat of emerging avian influenza, constant monitoring of AIVs should be conducted closely for agricultural and public health.
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Subtipo H5N1 del Virus de la Influenza A , Subtipo H7N9 del Virus de la Influenza A , Subtipo H9N2 del Virus de la Influenza A , Gripe Aviar , Gripe Humana , Animales , Humanos , Gripe Aviar/epidemiología , Subtipo H7N9 del Virus de la Influenza A/genética , Subtipo H9N2 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H7N2 del Virus de la Influenza A , Filogenia , Virus Reordenados/genética , Gripe Humana/epidemiología , China/epidemiología , MamíferosRESUMEN
Upon the occurrence of DNA double strand breaks (DSB), the proximal histone variant H2A.X is phosphorylated as γ-H2A.X, a critical signal for consequent DSB signaling and repair pathways. Although γ-H2A.X-triggered DNA damage response (DDR) has been well-characterized in yeast and animals, the corresponding pathways in plant DDR are less well understood. Here, we show that an Arabidopsis protein γ-H2A.X-INTERACTING PROTEIN (XIP) can interact with γ-H2A.X. Its C-terminal dual-BRCT-like domain contributes to its specific interaction with γ-H2A.X. XIP-deficient seedlings display smaller meristems, inhibited growth, and higher sensitivity to DSB-inducing treatment. Loss-of-function in XIP causes transcriptome changes mimicking wild-type plants subject to replicative or genotoxic stresses. After genotoxic bleomycin treatment, more proteins with upregulated phosphorylation modifications, more DNA fragments and cell death were found in xip mutants. Moreover, XIP physically interacts with RAD51, the key recombinase in homologous recombination (HR), and somatic HR frequency is significantly reduced in xip mutants. Collectively, XIP participates in plant response to DSB and contributes to chromatin stability.
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Arabidopsis , Histonas , Animales , Histonas/metabolismo , Cromatina/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Reparación del ADN , Roturas del ADN de Doble Cadena , ADN/metabolismo , Daño del ADNRESUMEN
Understanding the factors affecting the growth of plantation forests can reduce the loss of economic and ecological values caused by plantation forest subhealth. Plantation forests are widely distributed in hilly areas with microtopographic features. Microtopography influences climatic factors associated with plant growth, during not only general time but also extreme events like droughts. However, little research has been conducted on the effects of microtopography on the plantation forest growth. In this paper, we selected Pinus tabulaeformis planted in a hilly site, and studied the effect of microtopography on the climate-growth relationship and drought response of a typical plantation in Northeast China using dendroecological methods. We found: 1) Between hill positions, temperature caused a climatic growth difference. Compared to the hilltop, the correlation of annual growth on the hillside with monthly temperature was more negative in July-August and less positive in January-April. 2) Between aspects, precipitation intensities caused a climatic growth difference. Compared to the sunny slope, the correlation of annual growth on the shady slope with monthly total precipitation below 10 mm/day was less positive (May-June) or more negative (March-April and July), while that with monthly total precipitation above 10 mm/day was more positive in most months.3) Drought response varied significantly based on hill position and aspect. There was no significant difference in resistance between hill positions, while recovery and resilience on the hilltop were greater than those on the hillside.Resistance, recovery, and resilience were all lower on the sunny slope than those on the shady slope. Overall, microtopography exists the effects on the growth of plantation forests, both in terms of climate-growth relationships in general climate and in response to drought when extreme events. Meanwhile, the climatic factors that caused the difference in growth of plantation forests between hill positions and aspects differed. The difference in growth between hill positions was caused by temperature, while that between aspects was caused by precipitation intensity. Drought response difference reflected the legacy effect of drought on plantation growth, which could lead to subsequent changes in climate-growth relationships. These findings demonstrate that strengthening the research of forest trees on microtopography is necessary for accurate carbon sink assessment and precise forest management.
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Background: Severe fever with thrombocytopenia syndrome (SFTS) is a novel infectious disease with no specific therapeutics and vaccines. We hypothesize that health education in vulnerable people would ameliorate their knowledge, attitudes and practices (KAP) regarding SFTS and reduce its prevalence. Methods: A four-stage cluster cross-section study in sixteen community units was performed. Sixteen groups were allocated to the intervention or control groups. A 6 months education program was administrated. The primary outcome was KAP scores 6 months after intervention. Predictors of KAP score changes were also analyzed. Results: Eight hundred and fifteen valid questionnaires pre-intervention and 767 ones post-intervention were retreated. No significant differences were found in demographic characteristics and KAP scores before intervention. A significant improvement in KAP score (16.8 ± 4.7 vs. 22.0 ± 4.2, p < 0.001) in the intervention group was observed compare with the controls. Educational level and intervention program were the common predictors of KAP score changes. Conclusions: Education improved KAP scores in SFTS vulnerable people which may contribute to the control of the disease.
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Síndrome de Trombocitopenia Febril Grave , Humanos , Conocimientos, Actitudes y Práctica en Salud , China/epidemiología , Educación en Salud , Encuestas y CuestionariosRESUMEN
As sessile organisms, plants are constantly exposed to changing environments frequently under diverse stresses. Invasion by pathogens, including virus, bacterial and fungal infections, can severely impede plant growth and development, causing important yield loss and thus challenging food/feed security worldwide. During evolution, plants have adapted complex systems, including coordinated global gene expression networks, to defend against pathogen attacks. In recent years, growing evidences indicate that pathogen infections can trigger local and global epigenetic changes that reprogram the transcription of plant defense genes, which in turn helps plants to fight against pathogens. Here, we summarize up plant defense pathways and epigenetic mechanisms and we review in depth current knowledge's about histone modifications and chromatin-remodeling factors found in the epigenetic regulation of plant response to biotic stresses. It is anticipated that epigenetic mechanisms may be explorable in the design of tools to generate stress-resistant plant varieties.
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METTL4 belongs to a subclade of MT-A70 family members of methyltransferase (MTase) proteins shown to mediate N6-adenosine methylation for both RNA and DNA in diverse eukaryotes. Here, we report that Arabidopsis METTL4 functions as U2 snRNA MTase for N6-2'-O-dimethyladenosine (m6Am) in vivo that regulates flowering time, and specifically catalyzes N6-methylation of 2'-O-methyladenosine (Am) within a single-stranded RNA in vitro. The apo structures of full-length Arabidopsis METTL4 bound to S-adenosyl-L-methionine (SAM) and the complex structure with an Am-containing RNA substrate, combined with mutagenesis and in vitro enzymatic assays, uncover a preformed L-shaped, positively-charged cavity surrounded by four loops for substrate binding and a catalytic center composed of conserved residues for specific Am nucleotide recognition and N6-methylation activity. Structural comparison of METTL4 with the mRNA m6A enzyme METTL3/METTL14 heterodimer and modeling analysis suggest a catalytic mechanism for N6-adenosine methylation by METTL4, which may be shared among MT-A70 family members.
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Arabidopsis , Metiltransferasas , Adenosina/análogos & derivados , Arabidopsis/genética , Arabidopsis/metabolismo , Metilación , Metiltransferasas/metabolismo , Nucleótidos/metabolismo , ARN/metabolismo , ARN Mensajero/metabolismo , S-Adenosilmetionina/metabolismoRESUMEN
[MnCr(oxalate)3]- possesses a two-dimensional ferromagnetic network that is an ideal system for the construction of multifunctional molecular materials based on ferromagnetism. This is because additional functions, such as ferroelectricity, can be hybridised by incorporating functional cations between the layers. However, the majority of [MnCr(oxalate)3]- networks readily incorporate solvent molecules upon crystallisation, and it is sometimes difficult to measure the crystal physical properties because of the collapse associated with desolvation. Upon desolvation, the polar crystal (CBA+)([18]crown-6)[MnCr(oxalate)3]-(CH3OH) (1·CH3OH) (CBA+ = 4-carboxybutan-1-aminium) underwent a crystal-to-crystal transformation to form (CBA+)([18]crown-6)[MnCr(oxalate)3]-, 1. Furthermore, this change was accompanied by hydrogen bond reorganisation in the (CBA+)([18]crown-6) supramolecular assembly. Both crystals exhibited ferromagnetic ordering at approximately 5 K. In crystal 1, a "merry-go-round" motion of [18]crown-6 was observed, with an activation energy of 41.41 kJ mol-1, which resulted in dielectric relaxation. This crystal-to-crystal structural transformation provides a strategy for designing multifunctional hybrid materials, in which an additional function arises from molecular motion.
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Water use efficiency (WUE) of five dominant tree species (Pinus koraiensis, Fraxinus mandshurica, Acer mono, Quercus mongolica, and Tilia amurensis) was estimated using the stable carbon isotope method in a broadleaved Korean pine forest in Changbai Mountains. Leaf carbon (C), nitrogen (N), and phosphorus (P) contents were measured to analyze nutrient utilization of the dominant species. The relationship between WUE and leaf nutrient contents was systematically assessed. WUE was different due to the variations of micrometeorological factors at different locations in the canopy. The four broadleaved tree species showed upper layer > middle layer > lower layer, while P. koraiensis showed upper layer > lower layer > middle layer. WUE of evergreen coniferous P. koraiensis was higher than that of two broadleaved species with diffuse-porous wood (T. amurensis and A. mono) and lower than that of two broadleaved species with ring-porous wood (F. mandshurica and Q. mongolica). The compound-leaved species (F. mandshurica) had the highest WUE. The WUE of new leaves was significantly higher than old leaves in P. koraiensis. The carbon content and C/N of the old and new leaves of evergreen coniferous P. koraiensis were significantly higher than those of the other four broadleaved tree species, while nitrogen content and N/P were significantly lower than those of the four broadleaved tree species. P content of old leaves of P. koraiensis was significantly lower than that of the four broadleaved tree species. P content of new leaves of current year was not significantly different from that of the broadleaved tree species. The WUE of five tree species had a poor correlation with leaf C content, but a positive correlation with leaf N content. The WUE of evergreen coniferous and deciduous broadleaved tree species was correlated with leaf P content but in opposite direction.